The present application relates to a control device, a storage device, and a storage control method. Especially, the present application relates to processing of management information for conversion from logical addresses into physical addresses.
Storage devices employing a non-volatile memory such as a NAND type flash memory, for example, have been widespread. A non-volatile memory is used in a memory card, a solid state drive (SSD), an embedded multimedia card (eMMC), and the like which are used in various types of electronic devices and information processing devices, for example.
Japanese Unexamined Patent Application Publication Nos. 2009-70098, 2007-334852, 2007-193838, and 2007-58840 have disclosed storage devices employing a flash memory.
In a non-volatile memory, a physical address is used as an address of a physical storage region. Accordingly, a physical block, a physical page, and a physical sector are set. A plurality of physical sectors constitute a physical page, and a plurality of physical pages constitute a physical block.
Deletion (erasing) is performed in a physical block unit and writing (program) and reading are executable in a physical page unit.
A logical address is used for address designation from a host device side. A logical block and a logical page according to a logical address are associated with the above-described physical address. Accordingly, a logical address is converted into a physical address in response to an access request and access to an actual flash memory is executed.